A refined geometric correction algorithm for spotlight and sliding spotlight spaceborne SAR

In this paper, a novel algorithm of geometric correction for spotlight and sliding spotlight SAR is presented. Synthetic Aperture Radar (SAR), which is independently of weather and light conditions, is a well-established imaging technique for remote sensing [1]. With the increasing demands for higher resolution, spotlight and sliding spotlight modes have been presented. The key requirement for understanding SAR image is to map the location of pixels accurately, and this requires a more accurate geometric correction algorithm to assure the quality of spotlight and sliding spotlight SAR image products [2]. In 1982, a Range-Doppler location method, which is effective for stripmap SAR, has been presented by John C. Curlander [3], but it´s not effective for spotlight and sliding spotlight SAR. Considering the imaging process model [4], the space-time mapping relationship and the space-frequency mapping relationship, we have modified the location equations to improve the geometric correction for spotlight and sliding spotlight SAR. The simulation result shows the validity of the algorithm.